1. United Nations. World Urbanization Prospects: The 2014 Revision; 2015. doi: 10.4054/DemRes.2005.12.9.
2. Hot cities: Battle-ground for climate change;United Nations Habitat,2011
3. San Francisco Environment. San Francisco Citywide Greenhouse Gas Reduction Actions and Goals 2017. https://sfenvironment.org/article/citywide-actions-and-goals (accessed October 31, 2017).
4. NYC Sustainability. New York City Climate Change Goals; 2017. (accessed March 7, 2017).
5. U.S. Energy Information Administration. U.S. total energy annual review; 2017. (accessed June 4, 2017).